Hydraulic classifier



Get. M, 119%. 11,511,643

L. c. TRENT HYDRAULIC CLASSIFIER Filed Oct. 21. 1921 2 Sheets-Sheet 1 Ucik. 14 192%.

L. C. TRENT HYDRAULIC CLASSIFIER 21. 1921 2 Sheena-Shes- Filed Oct.

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LAMARTINE C. TRENT, 0]? WASHINGTON, DISTRICT OF COLUMBIA.

HYDRAULIC CLASSIFIER.

Application filed October 21, 1921. Serial No. 509,317.

To all whom it may concern:

Be it known that I, LAMARTINE C. TRENT, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in a Hydraulic Classifier, of which the following is a specification.

The invention relates to a process for classifying and. separating different sized particles from a mixed fiow of mineral matter, such as that flowing from crushing and pulverizing machines, used in the refining of coal and various ores.

The primary object of the invention is to classify and separate different sized products, such as coa1,'ores, and various minerals.

The invention has particular reference to the classiiying= of the various sizesin refining coal, and is particularly valuable in the preparation of fine coal foruse in connection with the Trent process.

Another object of the invention is to classify the various sizes of the ground coal and at the same time to concentrate or thicken the various classifications.

A further object ofthe invention is the provision ina hydraulic classifier, of means for regulating the classification of the ground material. 1

lt ith these general objects in view, and such others as will be apparent from the description, my invention resides in the novel construction, combination, and arrangement of parts, and the process hereinafter described and claimed, and taken in connection with the accompanying drawings, of which:

Figure l is a, vertical section of my improved classifiei";

Figure 2, a top plan view thereof;

Figure 3, a detail vertical section .of the bottom of the classifier;

Figure l, a detail vertical section of the agitating mechanism employed; and

Figure 5, a vertical section of a modified form of-classifier.

In grinding coal. in a wet state sufliciently fine for certain meiods of refining, it is necessary to grind it to extreme neness after it has been partially crushed to sizes not exceeding one-half inch in diameter, and when reduced to such size it--must be delivered into a classifier which will remove the released impurities existing in the coal, comprising slate, shale, and other rocks, which are incombustible and vaiuelese, and being harder, are dificult to grind and separate, The classifier must separate the coal into three or more products, namely the undersize, which is extremely fine and capable of passing a two hundred mesh screen, the oversize, which is to be returned to the fine grinding machine for a' finer grinding, and the coarse impurities, consisting of stone and incombustible mineral particles usually containing iron pyrites, the principal source from which coal becomes contami mated with sulphur.

My improved classifier is so constructed as to acoom lish this classification in a novel and e cient manner and is so arranged that an exceedingly fine degree of adjustment may be obtained for the regulation of the classification, whereby a practically pure product is obtained in the final step of the process.

In detail, the invention comprises a tank 1 having a fiat bottom 2 and provided with tapering side walls. In the preferred form of the invention, the tank is preferably cylindrical, the walls thereof sloping o'utwardly from the bottom to the top, as clearly illustrated in Figure 1. The tank is mounted on a suitable supporting base 3, and is provided at its top edge with an annular trough 4 disposed on the interior of the tank, substantially flush with the top thereof and adapted to receive the overflow containing the finely ground material which it is desired to recover, and which is carried away from the tank by means of a pipe 5 disposed at the top of the tank. Extending across the top of the tank is a pair of suporting beams 6 suitably disposed for carrying thereon a late 7 secured to the beams and disposed a ove the center of the tank.

The plate 7 is provided with acentral bore 8 adapted to receive therethrough a depending shai't 9, which may be formed of. pipe sections, or solid if desired, and which is supported on the plate 7 by a ball bearing 10 disposed in a raceway 11 on the upper face of the plate and retained in position by means of a clamping collar 12 on the up er end of the shaft. This construction provi es for a free suspension of the shaft 9 within the tank and permits of a free rotation of the shaft. The upper end of shaft 9 is pro- ,vided with an eye 13 whereby the shaft may be raised or lowered for vertical adjustment when desired. The lower end of the shaft extends down into the tank tor a cens dera tlll Mill

his distance, and is threaded or otherwise suitably secured to a five way pipe joint 14, carrying four distributin pipe sections extending laterally there'rom, said sections having at spaced intervals thereon depending nozzles 15 disposed at an angle of approximately 65 to 67 degrees, the lower ends 0% the nozzles being provided with jet tips 1 a The lowerend of the joint 14: is threaded to receive a sleeve 18 depending therefrom and engaging over the upper end of 'an inlet pipe 19 extending upwardly through the bottom of the tank and in connection. with an inlet supply pipe 20 at the exterior of the tank. The sleeve 18 is of a sufficient internal diameter to provide for a spaced relation between the sleeve and the upper end of the pipe 19, whereby free rotation of the distributing members 15, maybe obtained.

Surrounding the upper end of the shait 9 in spaced relation, and extending downwurdly from the top of the tank to within a short distance above the joint 14, is a perforated cylindrical casing 60 in connection at its upper end with a hopper 21, disposed beneath a feed launder 22, from which the ground material to be classified is fed into the tank.

A short distance below the top of the tank, an annular suction pipe 23 is disposed on the interior of the tank, being formed of a wooden casin 24:, the wall of the" tank forming one Wal of the casing. The bottom 25, of the casing, is provided with a plurality of spaced apertures 26 forming intakes, and the entirepipe 23 is in connection with the water circu sting system by means of a pipe smtion 28, provided with a valve 29, and in connection with a pipe 30 extending downwardly to the inlet end 31 of a force pump 32 mounted on a suitable base 33 and adapted to be driven by suitable motor mechanism 34. The pump 32; is connected at its outlet end with the tank' inlet pipe 20, which is provided with a valve 34, and arranged between the inlet and outlet connections of the pump is a icy-pass 35 controlled by a valve 38. Adjacent the lower end of the tnnlr an outlet pipe 37 extends from the tank into the pipe section 30 of the water circulation system, and is controlled by a valve 88 whereby the circulation may be regulated. Suitabl arranged adiacent the lower end of the tan is-a-n outlet comprising a pipe 39 eontrolied by a valve 40, which extends into the tank andis adapted to carry-away the oversize particles for regrinding, after which they are returned to the classltier.

A discharge pipe 11 is arranged substantially midway of the tank and in connection with the interior thereof for carrying oil the classified material in a thickened condition, and is controlled by a valve 42. At

trolled by means of valve mechanism 46 whereby regulation of the discharge may be obtained. The pipe section 47 connects pipe 30 with the discharge pipe 5 and a valve 48 is disposed in this section 47, for regulation of the flow therethrough, as desired.

A \normal circulation of water within the tank and the various connections, is set up by operation of the pump 32, whereby water will be pumped into the tank through the pipe 1%),"j0int 14, distributing'sections 15 and nozzles 16, toward the bottom of the tank from which it will flow upwardly to the suction inlets 26, through pipe 23, pipe 28, and back through pipe 30 to the inlet end of the pump. This is the normal circulation within the apparatus, and as a means of regulating the classification of the ground material circulated with the water.

and held in suspension therein, I provide for the admission of extraneous water into the system by means of an inlet pipe 49 connected with the system by an elbow 15 disposed adjacent the inlet end 31 of the pump, and controlled by a valve 51.

In the modification illustrated in ,Figure 5, in which parts similar to those of the preferred form are indicated by primed numerals, the construction of the various elements of the device is the same, substantially, as in the preferred form; the tank 1' being provided with the tops 43', distributing pipe sections 15', shaft 9, and inlet connection 20. The discharge for the coarse material to be regreund, comprises in this instance, a perforated pipe 39' extending. into the interior of the tank. In this modisuction nozzles 52 extending into the tank at vertically spaced intervals and in connection with the pump return pipe 53 by means of sections 54 controlled by valves 55. The casing at the top of the tank is provided in this form, with a reduced lower end 56, the construction of the apparatus being in all other respects, substantially that of the preferred form.

In operation the tank is filled with water being circulated therethrough by operation of the force pump 32 in the manner described. The crushed coal to be classified is introduced from the feed launder 22, through hopper 21, down through the casing 60 into the tank, whereupon, the finer prodruinous note will be extruded through the perforations in the casing and the heavier material will be discharged at the lowerend of the casing above the joint 14, settling on the bottom of the tank at the center and surrounding the inlet pipe 19 to form a stratum A of the heavier material. Due to the force with which the water is caused to enter the tank, and the inclination of the nozzles 16, these nozzles and pipe sections will be caused to rotate and the jets of water from the tips 17 will be directed downwardly, impinging against the bottom of the tank, cut ting through, loosening, and agitating the stratum of coarse material accumulated on the bottom. of the tank. The upward flow of water rising through the .bed of agitated material will carry with it the finer particles of the coal, upwardly towards the suction intakes 26, through which the material will he returned through pipe and pump 32 to the classifier. Above the bed of impurities resting on the bottom of the tank and below the suction. intakes, a stratum of particles will be formed, as indicated at B, consisting of material too heavy to be carried u ward to the suction intakes 26, and

too lig t to remain in the bottom stratum of impurities. This stratum B comprises the oversize material-and tromthis stratum the material is drawn ofl' through the pipe- 39 and returned to the grinding mechanism from which it is, in turn, returned to the tank through the feed launder 22 for reclassification after regrinding. Ordinarily the fine material which it is desired to recover, would be carried through the suction intakes 26 owing to the tact that above the pipe 23 there is no circulation of water within the tank, As a means of recovering the extremely fine particles, extraneous water is admitted into the system by means of the pipe 49, the supply thereof being controlled by the valve 51, whereupon an excess of water will be supplied to the tank, which will cause a current to rise above the suction pipe 23 and overflow into the trough 4, carrying with it the line particles. in proportion as theextraneous water is admitted into the circulation system, the suction volume at the intakes 26 will be decreased and the upward flow of the water above-the pipe 28 will be sufiicicnt to carry with it only the extremely fine particles to the trough i, from which they are carried from the tank and system by means of the pipe 5.

in the modified form shown in Figure 5, the principle of operation is the same, ex cept that thesuction is controlled from various levels within the tank by means of the outlets 52 as described.

The impure and coarse particles resting on the bottom or the tank may be drawn oil from time to time through the discharge pipes i l, whereby the impurities will be examount of extraneous water admitted into the system; the control of the suction through pipe 23; manipulation of the bypass through its valve 36; control of the rate at which the oversize is returned to the grinding mechanism, by means of the valve 4:0; and the rate at which the material to be classified is fed through the feed launder and hopper. All of these foctors have a material bearing upon the degree of classification set up within the tank, as any ad justments therein will affect the velocity at which the particles are carriedthrough the tank, the consequent change in the velocity having a material effect on the formation oi: the various strata. The pulsating action of the water jets from the depending nozzles, disintegrating the stratum of heavy material on the bottom of the tank, will cause the various strata to be formed and concentrated according to the specific gravity of the materials and particles comprising the strata, whereby the machine becomes in effect, a concentrator as well as a classifier. If desired, the material having reached a certain degree of classification andiconcentration, may be drawn off through the pipe 41 While I have shown and described certain details and materials which enter into the construction and operation of the invention, and referred in detail to the various steps of the process, I desire it to be understood that 1 do not intend to limit myself to these, but that any such may be made use oi as will fall within the scope of the invention as claimed.

1 claim 2-:

1. A proces for hydraulic classification of ground material, comprising circulating water'upwardl T through a receptacle, feeding said material downwardly into said redeptacle, agitating the material collecting on the bottom of the receptacle,controlling the circulation cit-said water by admission of extraneous water into the system, and draw-- log off at certain points of the system the material held in suspension therein.

2. The process for hydraulic classification of ground material, comprisin circulating water upwardly through a tanir having an open top and provided with an inlet in the bottom thereof, and an outlet below the top' for the water of the circulation system, feeding said material by action of gravity into the tank against the u-pward flow of water therein whereby parts of said material will be held in suspension, agitating the material in the tank by directional flow of water therethrough, admitting extraneous water into the circulation system whereby an adjustable even flow; of water will be secured at the top of the tank for carrying ofi' extremely fine particles of the material held in suspension, and drawing oil at certain other points in the tank, the material held in suspension therein. 7

3 A process for hydraulic classification of ground material, comprising feeding said material into a circulating liquid system, against the flow thereof, controlling this rate of circulation of said system whereby the material may be held in suspension at different points, according to the variation of the rate of circulation, concentrating certain portions of the. material at certain points in the system, agitating said concentrations by directional flow of'the liquid, and drawing off at certain points of the system the material held in suspension therein.

4. A hydraulic classifier comprising, a tank having an. open top, closed bottom and outwardly diverging side walls extending from the bottom of the tank, a rotatable spider disposed on the botom of said tank, nozzles projecting downwardly from said spider, a water supply conduit connected through the bottom of said tank to said spider, means for feeding ground material into the top of said tank above said spider, means for drawing off water at certain portions of said tank and returning same to the water supply conduit, means associated with said conduit for maintaining a continuous circulation of water through the tank, said nozzles being so arranged as to cause a directional flow of the water for separating the ground material into zones accord g to specific gravity, and taps in the walls of said tank for drawing oil the mater al from the various zones as desired.

5'. A hydraulic classifier comprising, a receptacle comprising a tank having an open top and closed bottom with outwardly diverging side walls, a rotatable spider disposed on the bottom of said tank, a water supply conduit associated with said spider for rotating the same by action of water supplied thereto, means for circulating the water through said conduit, spider and tank in a continuous system, a perforated feeding pipe disposed in the tank above said spider or the reception of ground material to deliver the same within the tank, said spider being disposed within the tank to agitate the ground material therein by directional flow of water issuing therefrom, and means in the walls of the tank for drawing ofi' material held in suspension at different levels.

In testimony whereof I afiix my signature.

LAMARTINE G. TRENT. 

